5/21: Tornado in Moore, Okla., was an EF5, the most powerful there is

May 21, 2013, 6:30 PM|The twister that plowed through Moore, Okla., injured more than 300 people and caused at least 24 deaths ; Also, a third-grade teacher at Plaza Tower Elementary School in Moore, Okla., did everything she could to save her students; And, Glenn Lewis, the mayor of Moore, Okla., was there in 1999 when another tornado devastated the city. He speaks to Scott Pelley about how the town will rebuild following Monday's disaster.